Stainless steel pipe is a hollow and longitude steel, economical steel section is circular. Stainless steel pipes have been widely used in petroleum, chemical, medical, food, light industry, equipment and structural parts, etc. Also, when torsional and torsional strength are equal, stainless steel is lighter, so it is used for equipment parts and project structures. It is also used to produce barrels and shells for various conventional weapons. This kind of pipe is divided into: stainless steel seamless pipe and stainless steel welded pipe.